Casting steel strip
AssigneesIshikawajima-Harima Heavy Industries Co., Ltd., BHP Steel (JLA) Pty Ltd.
InventorLazar Strezov
Life of this patent
Estimating the term…
Abstract
Method of casting steel strip in which molten steel solidifies as a shell on a chilled casting surface (100). The casting surface (100) has a texture (101) formed by a regular pattern of surface projections (103) and depressions (102) and the steel chemistry is selected to generate in the casting pool deoxidation products which form on the casting surface (100) a layer of less than 5 microns thickness a major proportion of which is liquid during cooling of the steel to below its liquidus temperature in the formation of said solidified shell. The substantially liquid layer suppresses the formation of surface defects in the solidifying metal surface due to early deposition of solid oxides on the casting surface.
Claims21
A method of casting steel strip comprising:
- a) providing a chilled casting surface with a texture formed by a regular pattern of surface projections and depressions;
- b) contacting the chilled casting surface with a casting pool of molten steel to cause solidification of steel from the casting pool onto the casting surface as a solidified shell, and
- c) separating the solid shell from the casting surface in a solidified strip;
- wherein the molten steel casting pool contains deoxidation products forming on the casting surface a layer of less than five microns thickness, a major proportion of which is liquid during cooling of the steel to below the liquidus temperature in the formation of said solidified shell.
A method of continuously casting steel strip comprising:
- a) introducing molten steel into a nip between a pair of parallel chilled casting rolls to form a casting pool of the molten metal supported on the casting surfaces of the rolls immediately above the nip, said casting surfaces being textured by a regular pattern of surface projections and depressions;
- b) rotating the rolls to cause solidified steel shells forming on the casting surfaces in contact with the casting pool to be brought together into a solidified steel strip delivered downwardly from the nip;
- and
- c) forming on each of the casting surfaces during metal solidification a layer of oxide material, a major proportion of which is liquid during cooling of the steel to below its liquidus temperature in the formation of said shells, said molten steel having a composition selected so as to form said oxide material from the molten steel, said oxide material being deposited on the casting surfaces by the rotation of the rolls in contact with the molten steel to form said layer, said oxide material forming liquid oxide phases at the casting temperature to produce said major proportion of liquid in the layer.
A method of casting steel strip comprising:
- a) providing a chilled casting surface with a texture formed by a regular pattern of surface projections and depressions;
- b) contacting the chilled casting surface with a casting pool of molten steel to cause solidification of steel from the casting pool onto the casting surface as a solidified shell;
- and
- c) separating the solid shell from the casting surface in a solidified strip;
- wherein the composition of the molten steel is selected to generate, in the casting pool, deoxidation products which form on the casting surface a layer of less than five microns thickness, a major proportion of which is liquid during cooling of the steel to below the liquidus temperature in the formation of said solidified shell.
Dependencies are inferred from the claim text.